ColumnTree Keyboard navigation doesn't work

Hi,
I have created a ColumnTree and it works super, though when I use the keyboard to navigate it behaves a little strange. I click on a node and it gets focus, then I start to navigate with the arrow keys. All nodes expand like they should but when I navigate to a leaf and press enter, focus is moved back to the node that received original focus (the one I clicked on). It's like focus isn't moved when I navigate with the keyboard. I used the ColumnTree example and haven't changed it.
//Erimat